Vehicles, such as motor vehicles, often include one or more crash structures configured to sacrificially deform in the case of a collision to prevent injury to vehicle occupants and/or damage to other components of a vehicle. Crash structures are often configured to dissipate as much energy as possible during their deformation. It is often desirable to minimize the deceleration of the vehicle during a collision, by minimizing the peak force experienced during deformation of the crash structure.
Many vehicles comprise an internal combustion engine, which is often provided towards the front of the vehicle. In the case of the vehicle colliding front on with an obstacle, the engine may collide with the obstacle before the crash structure has fully deformed. The momentum of the engine may represent a significant proportion of the momentum of the vehicle and hence, an impact between the engine and the obstacle may greatly reduce the momentum of the vehicle.
In vehicles with rear mounted engines, the momentum of the engine contributes to the total momentum of the vehicle throughout the full duration of a front on collision. Providing a crash structure for a vehicle with a rear mounted engine can therefore be challenging.